Hydrogenation involves the addition of molecular hydrogen to the unsaturated bonds of organic compounds. Nearly all such reactions require the presence of a catalyst to initiate, to sustain or to facilitate the reaction.
Copper chromite catalysts have been used for many years to hydrogenate carbonyl compounds and functional side rings of aromatic compounds. Following are some of the typical classes of reactions in which copper chromite catalysts are employed:
1. The hydrogenation of aldehydes to their corresponding alcohols. These reactions are usually carried out in liquid phase at a pressure of between 1 and 10 atmospheres and a temperature of between 120.degree. C. and 160.degree. C.
2. Conversion of fatty acids or methyl esters of fatty acids to saturated fatty alcohols. These are typically carried out as slurry phase or fixed bed trickle phase reactions at temperatures between 250.degree. C. and 300.degree. C. and pressures of between 170 and 300 atmospheres.
3. Hydrogenation of furfural to furfuryl alcohol. This is a liquid phase reaction, using a barium stabilized copper chromite catalyst, typically conducted at 50 atmospheres pressure and a temperature between 160.degree. C. and 200.degree. C. If carried out as a trickle phase reaction, a pressure of about 14 atmospheres and a temperature of about 170.degree. C. is used.